Indicating fuse



Uc. T0, T939. y F. A. SCHILLER zfrnggy INDICATING FUSE Filed Aug. 5, 1936 2 Sheets-Sheet 2v Peteniea oei. 1o, 1939 i 2,175,919

VUNiTED STATES PATENT oFFicE INDICATING FUSE Frederick A. Schler, Newark, N. J., alsignor to Indicator Corporation, Newark, N. '1., a corporation of New Jersey Application August 5, 1936, Serial No. 94,323

11 Claims. (Cl. 20D- 121) 'I'his invention relates `in general to electric Figure 4 is a horizontal sectional view on the fuses, and especially'to fuses of the cartridge line 4-4 of Figure 3. type, one object of the invention being to provide Figures and 6 are transverse sectional views novel and improved means for indicating the inon the lines 5 5 and 6 6 of Figure 3.

6 tegri'ty of the fusible element of the fuse, that is Figure 'I is a wiring diagram showing the conto indicate rupture of the fuse as the result of nection of the electrical indicating means to the the passage of abnormal current therethrough. electrical conducting members of the'indicatory Another object of the invention is to provide a unit. fuse of this character which shall include a Figure 8 is a side elevation of another type of 10 simple and inexpensive visible indicator which cartridge fuse and an indicator unit embodying 10 can be easily and quickly physically and electria modification of the invention releasably concally connected to the fuse. nected to the fuse.

A further object is to provide an integrity in- Figure 9 is a top plan view of the structure v dicating unit for electrical fuses which shall Asi'iown in Figure 8.

l5 comprise a case including separably connected Figure 10 is a transverse sectional view on the l5 complemental sections forming a chamber beline IIi--ili of Figure 8, the fuse being shown in tween them in which is mounted electrical indiend elevation. cating means, and means for connecting the in- Figure 11 is a fragmentary side elevation of dicating means with the terminals of the fuse one end of a cartridge fuse of the form shown in n which shall include a pair of parts separably Figure 1, and a modiiication of the means for clamped and held between the casing sections, releasably connecting the indicator unit to the whereby simplicity of structure, assembly of fuse, and parts and connection of the indicating unit to a Figure 12 is a sectional view on theline I2I2 fuse, shall be achieved.. of Figure 11.

u Another object is to provide a combination of Specifically describing the invention, for the fuse and integrity indicator of the character depurposes of illustration I have shown the invenscribed wherein a common means is utilized for tion in connection with a known type of cartridge physically and electrically connecting the indifuse, although the invention is susceptible of use Y eating means of the indicator to the terminals of with other types of fuses. the fusible element. E t Referring to Figures 1 `to 'I inclusive the rei- 30 Other objects are to provide an indicator unit erence character I designates a tubular housing which shall comprise a casing. formed of a pluof insulating material in each end of which is rality of complemental sections and having an fitted a sleeve or bushing 2 of electricity conductelectricalindicating means suchas a glow lamp ing material having One end l PlOjeOtillE from :i3 within the casing, and electrical conducting parts the housing and connected to the terminals of 35 clamped between and interlocked with the casa fusible element I arranged within the casing. ing *sections for either directly' connecting the As shown, the fusible element has connected to indicator casing to a fuse'or connecting the caseach end a blade I for engagement with a tering to clips or the like for releasable engagemlnl clip on an insulating block 0f the Bilal 4 ment with the terminals ef a ruse, the said eiecnature. for example such'as the clip A- Secured 4o trical conductinglmeans also serving to connect t0 each blade is a collar t, and one blade h'as the electrical indicating means to the fuse ternotches 1 cooperating with keepers hinged t0 minals, and to obtain other advantages and results the corresponding bushing! for holding the fusi- 'as will bel brought out by the following descripble element and blades against longitudinal tionmovement in the housing. Terminal caps t of 4.5

p Referring to the accompanying drawings in known construction are threaded upon the outer which corresponding and like parts are desig' ends of the sleeves l.- The fuse structure so far nated throughout the several views by the same described is old in the art and no claim to novelty reference characters, is made thereon.

Figure l is a side elevation of a combination Heretofore, the sleeves 2 have been held 50 cartridge fuse and integrity indicator embodying against removal from the housins I by pins 0r my invention. rivets passing through the housing and the inner Figure 2 is a top plan view thereof. portions of the sleeves, but in accordance with Flsure 3 is a vertical longitudinal sectional my invention I eliminate the necessity for such view on the llne #-3 of Figure 2, pins and utilise in piece thereof conducting eieu ments which also serve to electrically connect anv J longitudinal alinement with the indicator casing.

electrical fuse integrity indicating means to the terminals `of the fuse. Specically I have shown a pair of screws It threaded through the housing l and each physically vand electrically connected to one sleeve 2, the heads Il of the screws projecting from theY exterior of the housing I; 'Ihese conducting elements or screws Il also serve to physically connect; the casing of my integrity indicator to the fuse housing. As show n, said casing comprises two identical and complemental approximately U-shaped sections I2 of suitable insulating material each of which has a recs I3 in one side to complement the recess intheothersectionfor formingachamberwhen the sections aresecured together in side byside relation. heh section also has a socket Il in eacharmthu'eofoomplementaltothecorrespending socket of the ethnsection to receive the healbdportims II of the mrews when the sectiansaresecuredtogether- In securing the casing to the fuse sidesotthescre'sllmastosettheheadsof thescrewsintheslzkets II-aitervhichthesectimsaresecuredtogefhu'asbybnltsliwhichare Before the casing sections are secured to the meanssdmwninfheformofa glow lamp I6, knownintbe art,;and areais'tor I1 which ne electerminalottheglowlampbeingoonnectedtoone screwr Il andonetermnaloftberes'iatorbeing connectedtotheotheracrewllasclearlyshown mFigures3,4a.nd"I. Thenwhenthe twosections areappliedtothe fusehousing, thelamp II, resistor "and the wiring connections are enclosed within the chambers I3 of the indicator casing. Preferably the two sections I2 of the indicator casing have complementa] notches Il in their edges to form a sight opening through whicli the lamp Ii may be viewed. `The lamp I6 and resistance I1 are electrically in series with each other but in shunt with the fusible element I.

In operation, when the fuseis connected in circuit and under normal conditions, the current ilows freely through the fusible element and the lamp IG is unlighted; but when the fuse becomes ruptured as by Jthe passage of abnormal current therethrough, the current will ow through the sleeves 2, screws Ill, resistor I1 and lamp I (i to cause the lamp to glow, which may i be viewed\through the sight openings I8.

The invention also contemplates the quick detachable or releasable connection of the indicator unit to a fuse. The identical indicator casing including the conducting members or screws I Il may be utilized for this purpose. For one form oi' fuse such as indicated at I9 in Figures 8 to 10 inclusive, a U-shaped conducting spring clip 20 has o ne arm secured to each conducting screw III by a nut 2|, the clips being resilient and of such size and shape that they may be slipped over and physically and electrically connected to the ends of the fuse terminals 22 to which are electrically connected the fuse element zlladisposed within the fuse housing. Preferably the casing sections l I2 of the indicator' will be notched at 23 to provide a clearance for the nuts 2| and clips 20 so as to permit the indicator casing to rest on the fuse housing as shown in Figure 8; and these notches also prevent pivotal movement of the clips 20 on the screws I9 and hold the clips in Another form of the invention is shown in Figures 11 and 12 where the indicator casing has aclip 24 at each end for quick detachable or releasable connection to a blade type cartridge fuse like that shown in Figure 1. Here one arm of each clip 24 is hooked at 25 to engage under one edge of the corresponding blade 5 of the fuse, and thehook may be somewhat resilient to cooperate with a lug 26 on the arm which may snap over the other edge of the blade and hold the clip in position. The indicator unit may be applied to the fuse as shown in Figure 12, the hook 25 being rst slipped under the blade as shown by dot and dash lines after vwhich the whole unit is pulled upwardly and swung inwardly of the fuse housing until the indicator casing rests upon the fuse housing.

yThe indicator casing also serv as a handle forappb'ingandremovingthe fusetoandfrom the terminal clips, the approximate U-shape of the casing providing adequate clearance for the in all forms of the invention.

The identical form of the casing sections make the sections interchangeable so as to maintain oost of manufacture and assembly at the minimum, and the clamping of the screws between thecasingsectionsmakespossibletheuseoftheV mforeasilyand quicklysecuringthecasingdirectlytoafuse,andalsoforattachingthe uaeengagingclipszlandlltothecasingfor quid detachably and releasably mounting the indicator on thefuse housing. Thescrews thusserve the dual function of electrical conductors between theindlcating means and the fuse terminals and of physical fasteners for securing the indicator casing on the fuse.

Other modiilcations and changes in the details of structure of the indicator unit will occur to those skilled in the art as within the spirit and scope of the invention.

Having thus `described my invention, what I claim is:

1. An integrity indicating unit for fuses comprising a casing including complemental sections each having a recess to complement the recess in the other section for forming a chamber between the sections when they are secured together, means for separably securing the sections together, electrical indicating means within said chamber, and means for connecting said indicating means in shunt with the terminals of a fuse including a pair of parts separably clamped and held between `said casing sections.

2. An integrity indicating unit for fuses comprising a casing including complemental sections each having a recess to complement the recess in the other section for forming a chamber between the sections when they are secured together, means for separably securing the sections together, electrical indicating means Within said chamber, and means for connecting said indicating means in shunt with the terminals of a fuse Jincluding a pair of screws having their heads clamped and held between said casing sections and their Shanks projecting from said casing.

3. An integrity indicating unit for fuses comprising a casing including a pair of identical approximately U-shaped complemental sections each having a recess in one side to complement the recess in the other section for forming a chamber when the sections are secured together in side-by-side relation, means for separably securing the sections together, electrical indicating means in said chamber, a means for connecting said indicating means in shunt with the terminals of a fuse including a pair of parts one separably clamped and held between the complemental pair of end portions of the arms of said casing sections at each end of the casing.

4. An integrity indicating unit for fuses comprising a casing including a pair of identical approximately U-shaped complemental sections 'each' having a recess in one side to complement the recess in the other section for forming a chamber when the sections are secured together in side-by-sidel relation, means for separably securing the sections together, electrical indicating means in said chamber, a means for connecting said indicating means in shunt with the terminals of a fuse including a pair of screws each having its head clamped and held between the v complemental end portions of the arms of said casing sections at one end of the casing and with its shank projecting beyond the extremity of the corresponding arm of the casing.

5. A fuse comprising a housing of insulating material having conducting terminals and a fusible element within the casing electrically connected to said terminals, an integrity indicator comprising a casing including complemental sections each having a recess to complement the recess in the other section for forming a chamber between said sections when they are connected together', electrical indicating means within said chamber, and means connecting said indicating means in shunt with said fusibleelement including a pair of parts separably clamped and held between said casing sections and each electrically connected to one of said terminals.

6. A fuse comprising a housing of insulating material having conducting terminals and a fusible element within the casing electrically connected to said terminals, an integrity indicator comprising a casing including complemental sections each having a recess to complement the recess in the other section for forming a chamber between said sections when they are connected together, electrical indicating means within said chamber, and means connecting said indicating means in shunt with said fusible element including a pair of screws each having its head clamped and held between said casing sections and with its shank having a screw-threaded connection with one of said terminals.

secured to each of said parts for releasable, physical and electrical ccnnectionto one terminal of such fuse. c

8. A fuse comprising a housing of insulating material having conducting terminals and a fusible element within the casing electrically connected to said terminals, projections on the exterior of the housing'electrically connected respectively to said terminals, and an integrity indicator comprising a casing including complemental sections embracing said projections between them -ior securing the casing on said housing, and electrical indicating means within said casing electrically connected to said projections.

9. A fuse comprising a housing of insulating material having conducting terminals and a fusible element within the casing electrically connected to said terminals, projections on the exterior of the casing electrically connected respectively to said terminals, and an integrity indicator comprising a casing including separably connected complemental sections having complemental recesses to receive and interlock with said projections when said sections are applied to said projectionsv from opposite sides thereof and se cured together for fasteriing said casing to said housing, and electrical indicating means within said casing electrically connected to said projections.

10. A fuse comprising a tubular housing of insulating material, a sleeve tted into each end ofsaid housing and having an end projecting from said housing, a terminal element physically and electrically connected to said end of each sleeve, a fusible' element within said casing electrically connected to said terminal elements, an electricity conducting member passing through said housing and secured in and electrically connected to each of said sleeves with a portion projecting from the housing, and an indicator including a casing comprising separably connected comp'lemental sections embracing said projecting portions of said conducting members between them and interlocking therewith for securing the casing on the housing, and electrical indicating means within said casing electrically connected to said electricity conducting elements.

11. An integrity indicating unit for fuses comprising a casing including a pair of identical approximately U-shaped complemental sections each having a recess in one side to complement the recess in the other section for forming a chamber when the sections are secured together in side-by-side relation, means for separably seicuring the sections together, an electricity conducting element separably clamped and held between the complemental pair of end portions of the arms of said casing section and projecting from the corresponding end oi' the casing, and electrical indicating means within said chamber and electrically connected to said conducting elements.

FREDERICK A. SCHILLER. 

